DUP and UUP members have some hard thinking to do, and not just about who should lead their parties. There are also questions to be asked over how they should build for the future, and respond to a slide in votes.
The issue of unionist realignment — the two parties forming a single Stormont bloc — is now firmly on the agenda.
Whether that would do anything to make Assembly politics more functional or attractive is very much open to question.
The chief motivation of those pushing for unionist unity is to stop Martin McGuinness becoming First Minister. But it is by no means certain that such a defensive mindset would prove a hit at the polls.
The DUP fought last year's European Election on a platform of preventing Sinn Fein topping the polls. It did not work.
The party had better fortunes in the General Election under the slogan: “Let's keep Northern Ireland Moving Forward”.
It saw off the TUV, comfortably outpolled UCUNF and retained eight of its nine seats.
In the wake of the Euro election and the Iris Robinson scandal, the DUP high command would have bitten your hand off for such an outcome a few months back.
But the fact that it was Peter Robinson's East Belfast seat which fell changed everything. Also, the DUP's success can’t be divorced from the disaster of UCUNF.
It's easier to win when your opponent keeps aiming a sawn-off shotgun at his own feet.
The DUP's problems do not begin and end in East Belfast.
Its overall share of the vote fell from 33.7% in 2005 to 25% this time. Even when factoring in the decision not to fight North Down and Fermanagh/ South Tyrone, that's still quite a drop.
At a rough estimate, some 60,000 voters have deserted it.
The picture for the UUP is more bleak. It had a disastrous General Election in 2005, when it received a 17.7% vote share. Last week, it received 15.2%.
Quite senior UUP members have admitted in private that they are not Tories. Yet they still seemed to expect unionist voters — even in working class districts — to happily help put David Cameron in Downing Street.
The party also tried to have it both ways. Alongside rhetoric about change and real politics, the impression was often given that UCUNF was really all about having friends in high places and a pro-union Prime Minister.
The UUP will now have a leadership vacancy. The DUP can be expected to hunker down. There will be a lot of talk about how it is a family that sorts things out behind closed doors.
Family disagreements can sometimes be vicious, of course.
So far the only big idea seems to be realignment. But surely a real debate should go beyond the old idea of tribal solidarity?
Sooner or later, someone is going to have to ask questions about realigning politics here more generally — and breaking down the old divisions.